Hostname: page-component-7c8c6479df-fqc5m Total loading time: 0 Render date: 2024-03-28T20:51:57.162Z Has data issue: false hasContentIssue false

First records of the West African torpedo in Cabo Verde Archipelago, eastern Atlantic

Published online by Cambridge University Press:  01 March 2022

Sara S. Ratão
Affiliation:
Fundação Maio Biodiversidade, Cidade do Porto Inglês, Maio Island, Cabo Verdesara.ratao@fmb-maio.org
Claire M. Sydeman
Affiliation:
Fundação Maio Biodiversidade, Cidade do Porto Inglês, Maio Island, Cabo Verdesara.ratao@fmb-maio.org
Péricles Neves Silva
Affiliation:
Instituto do mar, Mindelo, Cabo Verde
Bernard Séret
Affiliation:
Ichtyo-Consult, Igny, France

Abstract

Type
Conservation News
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence CC BY 4.0.
Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press on behalf of Fauna & Flora International

Torpedo rays are small to large electric rays with a depressed circular disc, short snout, and tail with two dorsal fins. Most are benthic species living on soft sand and mud. They occur worldwide, from cool temperate to tropical waters, in the Atlantic, Indian and Pacific Oceans. The family Torpedinidae comprises two genera and 20 known species, of which two have been recorded in the waters of the Cabo Verde archipelago in the eastern central Atlantic: Torpedo marmorata and Torpedo torpedo.

The West African torpedo Torpedo mackayana is a small ray (maximum total length c. 50 cm) that lives at depths of 15–50 m, distinguished by a greyish brown dorsal coloration with white blotches irregularly scattered on its disc and tail. Its population is decreasing, and it is categorized as Endangered on the IUCN Red List. In the eastern central Atlantic, T. mackayana is known from Mauritania to Angola, including São Tomé and Príncipe, but has never previously been recorded in the Cabo Verde archipelago.

Here we report the first records of T. mackayana off Maio Island, east of Cabo Verde (Fig. 1). The first sighting was on 2 March 2019 whilst snorkelling off Bitxe Rotxa beach, Porto Inglês. Three individuals of < 60 cm total length were observed during 15.24–16.00, at different locations along the beach at 5–8 m depth, by SSR and CMS. The second sighting, an individual of c. 50 cm total length, was on 16 April 2021 under the pier on Bitxe Rotxa beach, at 11.00 at a depth of 7–8 m, by PNS. The third sighting was of an individual of < 50 cm total length, at c. 12.00 on 13 January 2022, also at Bitxe Rotxa beach. The individual was found alive on the sand and was returned to the water by local people and tourists.

The West African torpedo Torpedo mackayana photographed off Bitxe Rotxa beach, Porto Inglês, Maio Island, in March 2019 (left; Photo: Claire M. Sydeman), April 2021 (middle; frame snapshot from a video: Péricles Neves Silva) and in January 2022 (right; frame snapshot from a video: Jair Rocha).

This benthic coastal species, with no known pelagic phase in its life cycle, would have had to cross the ocean to reach Cabo Verde, which is c. 600 km from Senegal. We suspect this species can undertake long pelagic migrations, similarly to that of the great torpedo Tetronarce nobiliana. The conservation status of elasmobranchs in the waters of Cabo Verde is poorly known, and little attention has been devoted to electric rays because they are discarded as bycatch, with no commercial value. Research is required, including tagging, to improve knowledge of their status and distribution, and of any threats. We recommend an examination of a T. mackayana specimen from Cabo Verde, and surveys for this species around Sal and Boavista Islands as they share the same continental shelf as Maio, and similar habitat conditions and distance to the African continent.

We thank Rui Freitas, Peter Psomadakis and the EAF-Nansen Programme of FAO for their support, insight and expertise.